The present invention relates to methods and apparatuses for recognizing the shape of solid objects. More particularly, the invention relates to a method for recognizing the shape of solid objects in which light from a photoelectric sensor in a cylindrical rotary unit rotating at high speed is applied to a moving object to detect the actual projection pattern (shadow pattern) of the object thereby to recognize the solid figure of the object and an apparatus for practicing the method.
Heretofore, for selection, determination, measurement and inspection of solid objects including both natural products and industrial products, either a visual inspection method using the human eye or a relatively simple mechanical or electrical technique was employed to recognize the shapes and characteristics of objects.
Visual inspection is advantageous in that objects can be recognized with a high accuracy because recognition is achieved precisely. However, the visual inspection is still disadvantageous in that the inspector may make errors depending on environmental conditions such as the colors and glosses of objects and the available illumination. If his eyes become fatigued, then he can no longer continue the visual inspection. As for objects having unavoidable variations from item to item, the standard of decision may fluctuate depending upon the individual inspector and a fatigue factor. This is an unavoidable drawback accompanying the visual inspection method.
With a mechanical or electrical technique, the objects are recognized one-dimensionally or two-dimensionally with reference to predetermined standardized data. Thus, such a method is relatively simple. In this method, if objects to be recognized do not vary, then a fixed system suitable for the standardized properties of the objects can be provided. However, if the objects to be inspected are changed, then the system becomes completely useless. That is, the fundamental measurements of the system must be re-established in conformance with the new objects. This is a serious difficulty accompanying the conventional method utilizing a mechanical or electrical technique.
The invention is intended to eliminate the above-described drawbacks accompanying conventional object recognizing techniques.
A first object of the invention is to provide a method in which the shape of a solid object, that is, the three-dimensional figure of an object, is accurately recognized with a high accuracy and to provide an apparatus for practicing this method.
A second object of the invention is to provide a method and corresponding apparatus in which the shape of a solid moving object is automatically recognized at high speed and selection, measurement and inspection of objects are automatically carried out with less labor according to properties of the objects such as shape, partial sampling characteristic, non-uniformity, disposition, volume and size.
A third object of the invention is to provide solid object shape recognizing method and an apparatus for practicing the method adapted to be utilized in conjunction with other machines, devices and tools to automatically conduct the selection, measurement and inspection of objects with less labor required.